As a process for the preparation of ethers using phenol derivatives as starting materials, the Williamson synthesis is known in which halides are reacted in the presence of an alkali. The synthesis is described in Organic Synthesis, Vol. I, p. 435 (1941). In general, however, these halides are commercially available only with difficulty; in particular, halides containing an ether bond in the molecule thereof are impossible to use as industrial starting materials. Diphenoxyalkanes, which are more simple compounds, have been prepared by reacting alkyl dihalide with phenols. However, aromatic ethers having two or more --O-- linkages, such as diaryloxy alkane, have not been synthesized under mild reaction conditions in high yield.